CHANGES IN 'HAYWARD' KIWIFRUIT ATTRIBUTES AS A FUNCTION OF CUMULATIVE DEGREE-DAYS
During storage at 0.5°C, 10°C, 15°C and 20°C, flesh firmness, flesh lightness and flesh chroma of 'Hayward' kiwifruit decreased, while soluble solids content increased, all as exponential functions of the cumulative degree-days (DD) of the storage treatments. Fruit skin colour parameters (L, C and h° measured externally) decreased as linear functions of DD. Concomitantly, visible-near-infrared (VNIR) absorbance increased as DD increased. The increase was most pronounced at 766 nm where the absorbance was exponentially related to DD with a coefficient of determination (R2) of 0.48 on an individual fruit basis or 0.95 on a treatment basis. The chlorophyll absorption band around 672 nm was narrower but more extruded for fruit subjected to short time at low temperatures compared with that of fruit stored for longer time at higher temperatures. This was reflected more clearly by a trough at 684 nm and a peak at 700 nm in the second derivative spectra (D2). The log-transformed difference between the peak and the trough (LN(D2)=LN(D2(700)-D2(684)) related to DD with a R2 of 0.64 on an individual fruit basis or 0.91 on a treatment basis. This indicates that VNIR could be used to monitor fruit ripening during storage.
Feng, J., Brown, S.C., MacKay, B.R. and Maguire, K.M. (2007). CHANGES IN 'HAYWARD' KIWIFRUIT ATTRIBUTES AS A FUNCTION OF CUMULATIVE DEGREE-DAYS. Acta Hortic. 753, 777-784
Actinidia, temperature, firmness, fruit colour, flesh colour, soluble solids content, visible-near-infrared